KR102057715B1 - Light emitting device - Google Patents

Abstract

The embodiment relates to a light emitting device. The light emitting device according to the embodiment includes a light emitting structure sequentially comprising a first conductivity type semiconductor layer, an active layer and a second conductivity type semiconductor layer, a first transparent conductive layer disposed on the light emitting structure and including a concave portion. 1 may include an electrode pad disposed through the transparent conductive layer and in contact with the light emitting structure, and a branch electrode connected to the electrode pad and disposed in a recess.

Description

Light emitting device

The embodiment relates to a light emitting device.

Light Emitting Diode (LED) is a device that converts an electric signal into a light form using the characteristics of a compound semiconductor, and is used for home appliances, remote controllers, electronic displays, indicators, and various automation devices. There is a trend.

In general, miniaturized LEDs are made of a surface mount device type for direct mounting on a printed circuit board (PCB) board. Accordingly, LED lamps, which are used as display elements, are also being developed as surface mount device types. . Such a surface mounting element can replace a conventional simple lighting lamp, which is used as a lighting display for various colors, a character display and an image display.

As the usage area of the LED is widened as described above, the luminance required for a lamp used for living, a lamp for rescue signals, etc. increases, and thus, it is necessary to increase the luminous efficiency in order to increase the luminous luminance of the LED.

Such an LED includes an electrode on the transparent conductive layer, and the bonding force between the transparent conductive layer and the electrode is reduced by external moisture or fine dust, and the resistance to external pressure is reduced, so that the electrode is peeled. A phenomenon occurs.

On the other hand, Korean Patent No. 10-1067964 discloses a technical feature of etching part of the first electrode pad to expose the first conductive semiconductor layer, and reducing the peeling phenomenon by reducing the area where the electrode pad is in contact with the semiconductor layer. have.

Part of the transparent conductive layer is etched to a predetermined depth to form an electrode in the etched concave, or to increase the contact area between the transparent conductive layer and the electrode, thereby increasing the bonding force between the transparent conductive layer and the electrode To provide a device.

The light emitting device according to the embodiment includes a light emitting structure sequentially comprising a first conductivity type semiconductor layer, an active layer and a second conductivity type semiconductor layer, a first transparent conductive layer disposed on the light emitting structure and including a concave portion. 1 may include an electrode pad disposed through the transparent conductive layer and in contact with the light emitting structure, and a branch electrode connected to the electrode pad and disposed in a recess.

In the light emitting device according to the embodiment, the transparent electrode layer may be etched to a predetermined depth to form an electrode, thereby increasing the bonding force between the transparent conductive layer and the electrode.

In addition, further comprising a transparent conductive layer disposed to cover a portion of the electrode, it is possible to prevent the electrode peeling phenomenon, to prevent light absorption on the upper surface of the electrode, it is possible to improve the light extraction efficiency.

FIG. 1A is a view showing a plane of a light emitting device according to an embodiment, and FIG. 1B is a view showing an AA ′ section of FIG.
FIG. 2 is a diagram illustrating various embodiments of portion A of FIG. 1B.
3 and 4 are cross-sectional views of light emitting devices according to embodiments.
5 to 10 are views showing a manufacturing process of the light emitting device according to the embodiment.
11 is a cross-sectional view of a light emitting device package including a light emitting device according to the embodiment.
12A is a perspective view illustrating a lighting apparatus including a light emitting device module according to an embodiment, and FIG. 12B is a cross-sectional view illustrating C-C ′ of the lighting apparatus of FIG. 12A.
13 and 14 are exploded perspective views of a liquid crystal display including an optical sheet according to an embodiment.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, and only the embodiments make the disclosure of the present invention complete, and the general knowledge in the art to which the present invention belongs. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

The spatially relative terms " below ", " beneath ", " lower ", " above ", " upper " It may be used to easily describe the correlation of a device or components with other devices or components. Spatially relative terms are to be understood as terms that include different directions of the device in use or operation in addition to the directions shown in the figures. For example, when flipping a device shown in the figure, a device described as "below" or "beneath" of another device may be placed "above" of another device. Thus, the exemplary term "below" can encompass both an orientation of above and below. The device can also be oriented in other directions, so that spatially relative terms can be interpreted according to orientation.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, “comprises” and / or “comprising” refers to the presence of one or more other components, steps, operations and / or elements. Or does not exclude additions.

Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used in a sense that can be commonly understood by those skilled in the art. In addition, the terms defined in the commonly used dictionaries are not ideally or excessively interpreted unless they are specifically defined clearly.

In the drawings, the thickness or size of each layer is exaggerated, omitted, or schematically illustrated for convenience and clarity of description. In addition, the size and area of each component does not necessarily reflect the actual size or area.

In addition, the angle and direction mentioned in the process of describing the structure of the light emitting device in the embodiment are based on those described in the drawings. In the description of the structure constituting the light emitting device in the specification, if the reference point and the positional relationship with respect to the angle is not clearly mentioned, reference is made to related drawings.

FIG. 1A is a plan view showing a plane of a horizontal light emitting device according to the embodiment, and FIG. 1B is a cross-sectional view showing a cross-sectional view along the line AA ′ of FIG.

1A and 1B, the light emitting device 100 according to the embodiment may include a growth substrate 110, a buffer layer 120, a first conductive semiconductor layer 131, an active layer 132, and a second conductive semiconductor. The layer 133, the transparent conductive layer 140, the first electrode 160, and the second electrode 150 may be included. The second electrode 150 may include the electrode pad 151 and the branch electrode 152. It may include.

The growth substrate 110 may be formed of a conductive substrate or an insulating substrate. For example, sapphire (Al ₂ O ₃ ), SiC, Si, GaAs, GaN, ZnO, Si, GaP, InP, Ge, and Ga ₂ 0 It may be formed of at least one of _three . The growth substrate 110 may be wet-washed to remove impurities from the surface, and the growth substrate 110 may be patterned (Ptterned SubStrate, PSS) to improve light extraction efficiency, but is not limited thereto. .

The buffer layer 120 may be formed on the growth substrate 110 to mitigate lattice mismatch between the growth substrate 110 and the first conductive semiconductor layer 131 and to easily grow the conductive semiconductor layers.

The buffer layer 120 may be formed of AlInN / GaN stacked structure including AlN and GaN, InGaN / GaN stacked structure, and AlInGaN / InGaN / GaN stacked structure.

The light emitting structure 130 is positioned on the growth substrate 110 and may include a first conductivity type semiconductor layer 131, an active layer 132, and a second conductivity type semiconductor layer 133. The active layer 132 may be interposed between the semiconductor layer 131 and the second conductive semiconductor layer 133.

The first conductive semiconductor layer 131 is a semiconductor material having a compositional formula of Al _x In _y Ga _(1-xy) N (0 = x = 1, 0 = y = 1, 0 = x + y = 1), for example For example, it may be formed of any one or more of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN. It may also be formed using other Group 5 elements instead of N. For example, it may be formed of any one or more of AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP, and InP. In addition, when the first conductivity-type semiconductor layer 231 is an n-type semiconductor layer, for example, Si, Ge, Sn, Se, Te, or the like may be included as the n-type impurity.

The active layer 132 may be formed on the first conductive semiconductor layer 131. The active layer 132 is a region where electrons and holes are recombined. The active layer 132 transitions to a low energy level as the electrons and holes recombine, and may generate light having a corresponding wavelength.

The active layer 132 is, for example, including a semiconductor material having a compositional formula of _{In x Al y Ga 1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x + y≤1) It may be formed, and may be formed of a single quantum well structure or a multi quantum well structure (MQW).

Therefore, more electrons are collected at the lower energy level of the quantum well layer, and as a result, the probability of recombination of electrons and holes can be increased, thereby improving the light emitting effect. In addition, a quantum wire structure or a quantum dot structure may be included.

The second conductivity type semiconductor layer 133 may be formed on the active layer 132. The second conductive semiconductor layer 133 may be implemented as a p-type semiconductor layer to inject holes into the active layer 132. For example, the p-type semiconductor layer is a semiconductor material having a compositional formula of In _x Al _y Ga _{1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x + y≤1), for example It may be selected from GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, and the like, and may be doped with p-type impurities such as Mg, Zn, Ca, Sr, and Ba.

The first conductive semiconductor layer 131, the active layer 132, and the second conductive semiconductor layer 133 may be formed of metal organic chemical vapor deposition (MOCVD) or chemical vapor deposition (CVD). Deposition), Plasma-Enhanced Chemical Vapor Deposition (PECVD), Molecular Beam Epitaxy (MBE), Hydride Vapor Phase Epitaxy (HVPE), Sputtering It may be formed using, but is not limited thereto.

The transparent conductive layer 140 may be formed on the second conductive semiconductor layer 133.

The transparent conductive layer 140 is formed on the second conductive semiconductor layer 133 so that the current is uniformly diffused on the second conductive semiconductor layer 133. When the current is uniformly distributed on the second conductivity type semiconductor layer 133, light may be generated uniformly in the active layer 132, thereby increasing the light generation efficiency.

The transparent conductive layer 140 may be formed of a transparent material while being conductive to diffuse current. For example, indium tin oxide (ITO), aluminum zinc oxide (AZO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), and indium aluminum zinc (AZO) oxide), indium gallium zinc oxide (IGZO), indium gallium tin oxide (IGTO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IrOx, RuOx, RuOx / ITO, Ni / IrOx / Au, or Ni / It may be formed of at least one of IrOx / Au / ITO. However, it is not limited thereto.

The thickness of the transparent conductive layer 140 may be 600 to 2500 kPa. If the thickness of the transparent conductive layer 140 is thinner than 600 mA, the current diffusion efficiency is lowered. If the thickness of the transparent conductive layer 140 is thicker than 2500 kV, the transmittance of light generated in the active layer is reduced.

In addition, the transparent conductive layer 140 may include a recess 145 etched to a predetermined depth. The branch electrode 152 may be disposed in the recess 145, which will be described later.

Referring again to FIG. 1A, a first electrode 160 may be formed on the first conductive semiconductor layer 131, and a second electrode 150 may be formed on the transparent conductive layer 140. The second electrode 150 may include an electrode pad 151 and a branch electrode 152.

Further, by mesa etching from the second conductive semiconductor layer 133 to a part of the first conductive semiconductor layer 131, a space for forming the first electrode 160 can be secured, and the first conductive type can be secured. The first electrode 160 may be formed in an etched and exposed area of the surface of the semiconductor layer 131.

The second electrode 150 includes an electrode pad 151 connected to an external power source and a branch electrode 152 for dispersing current, and the electrode pad 151 and the branch electrode 152 are formed on the transparent electrode layer 140. Can be formed.

The electrode pad 151 may be disposed to contact the second conductive semiconductor layer 133 by penetrating the transparent conductive layer 140, and the branch electrode 152 may have a recess 145 of the transparent conductive layer 140. ) May be disposed.

At this time, the depth of the recess 145 may be 500 to 2000 500. If the depth of the recess 145 is shallower than 500 mm, when the branch electrode 152 is disposed in the recess 145, the force for coupling the branch electrode 152 so as not to be separated from the transparent conductive layer 140 is weakened. On the other hand, when the depth of the concave portion 145 is deeper than 2000 mm, considering the thickness of the transparent conductive layer 140, the concave portion 145 penetrates through the transparent conductive layer, so that the branch electrode 152 has a second thickness. It may be in contact with the conductive semiconductor layer 133.

In addition, although not shown, the first electrode 160 of FIG. 1A may also be formed to include an electrode pad (not shown) and a branch electrode (not shown), like the second electrode 150 described above. to be.

The first electrode 160, the electrode pad 151, and the branch electrode 152 may be formed of a conductive material, for example, indium (In), cobalt (Co), silicon (Si), and germanium (Ge). ), Gold (Au), palladium (Pd), platinum (Pt), ruthenium (Ru), rhenium (Re), magnesium (Mg), zinc (Zn), hafnium (Hf), tantalum (Ta), rhodium (Rh) ), Iridium (Ir), tungsten (W), titanium (Ti), silver (Ag), chromium (Cr), molybdenum (Mo), niobium (Nb), aluminum (Al), nickel (Ni) and copper (Cu) It may be formed of any one selected from) or two or more alloys, it may be formed by stacking two or more different materials.

2 is a diagram illustrating various embodiments of a second electrode of the light emitting device of FIG. 1.

Referring to FIGS. 2A and 2B, the cross-sectional shape of the recess 145 in which the branch electrode 152 is disposed may be polygonal or hemispherical. For example, as shown in FIG. 2A, when the width of the concave portion 145 is formed to become wider toward the upper portion, an area in which the transparent conductive layer 140 and the branch electrode 152 are in contact with each other increases, thereby providing transparent conductivity. Cohesion between the layer 140 and the branch electrode 152 may be increased.

In addition, as shown in FIG. 2B, even when the surface of the recess 145 is curved, the bonding force between the transparent conductive layer 140 and the branch electrode 152 may be increased for the same reason as described above.

Meanwhile, as shown in FIGS. 2A and 2B, the electrode pad 151 may be formed to increase the width of the electrode region in contact with the transparent electrode layer 140 toward the upper portion, thereby increasing the bonding force.

3 is a cross-sectional view of a light emitting device according to an embodiment.

Referring to FIG. 3, the light emitting device 200 may include a growth substrate 210, a buffer layer 220, a first conductive semiconductor layer 231, an active layer 232, a second conductive semiconductor layer 233, and a first substrate. The transparent conductive layer 241 and the electrode 250 may be included, and the electrode 250 may include an electrode pad 251 and a branch electrode 252. On the other hand, as compared to Figure 1 (b), it may further include a second transparent conductive layer 242. Hereinafter, the description of the same configuration will be omitted, and will be described mainly for the difference.

The second transparent conductive layer 242 may be disposed on the first transparent conductive layer 241, the branch electrode 252, and the electrode pad 251.

The second transparent conductive layer 242 may be formed to cover the entire upper surface of the branch electrode 252, and may include an opening that exposes a part of the upper surface of the electrode pad 251. In this case, power may be supplied from an external power source through the opening.

The second transparent electrode layer 242 may be formed thinner than the first transparent electrode layer 241 and may include the same material as the first transparent electrode layer 241. For example, indium tin oxide (ITO), aluminum zinc oxide (AZO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), and indium aluminum zinc (AZO) oxide), indium gallium zinc oxide (IGZO), indium gallium tin oxide (IGTO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IrOx, RuOx, RuOx / ITO, Ni / IrOx / Au, or Ni / It may be formed of at least one of IrOx / Au / ITO. However, it is not limited thereto.

As described above, when the second transparent electrode layer 242 is formed, the bonding force between the branch electrode 252 and the electrode pad 251 and the first transparent electrode layer 241 may be increased to prevent the peeling phenomenon. In addition, when the second transparent electrode layer 242 is formed of a dielectric material, light may be prevented from being absorbed by the electrode 250, thereby improving luminous efficiency of the light emitting device.

4 is a view showing a cross section of a vertical light emitting device according to the embodiment.

Referring to FIG. 4, the light emitting device 300 according to the embodiment includes a support substrate 310, a conductive layer 370, a first conductive semiconductor layer 331, an active layer 332, and a second conductive semiconductor layer ( 333, the second electrode layer 360, the first electrode 350, and the transparent conductive layer 340.

Compared with the embodiment of FIG. 1, there is a difference that further includes a support substrate 310, a conductive layer 370, and a second electrode layer 360. Description of the same components will be omitted below.

Support substrate 310 may be formed of a conductive material, for example, gold (Au), nickel (Ni), tungsten (W), molybdenum (Mo), copper (Cu), aluminum (Al), tantalum ( Ta), silver (Ag), platinum (Pt), chromium (Cr), Si, Ge, GaAs, ZnO, GaN, Ga ₂ O ₃ or SiC, SiGe, CuW, or any one of two or more alloys It may be formed by stacking two or more different materials.

The support substrate 310 may facilitate the emission of heat generated from the light emitting device 300 to improve the thermal stability of the light emitting device 300.

A coupling layer (not shown) may be formed on the support substrate 310 to couple the support substrate 310 to the conductive layer 370. The bonding layer (not shown) is, for example, a group consisting of gold (Au), tin (Sn), indium (In), silver (Ag), nickel (Ni), niobium (Nb), and copper (Cu). It may be formed of a material selected from or alloys thereof.

The conductive layer 370 is a material selected from the group consisting of nickel (Ni-nickel), platinum (Pt), titanium (Ti), tungsten (W), vanadium (V), iron (Fe), and molybdenum (Mo). Or they may be made of an alloy optionally included.

The conductive layer 370 can be formed using a sputter deposition method. When using a sputtering deposition method, when ionized atoms are accelerated by an electric field and collide with the source material of the conductive layer 370, atoms of the source material are ejected and deposited. In addition, according to the embodiment, an electrochemical metal deposition method, a bonding method using a eutectic metal, or the like may be used. In some embodiments, the conductive layer 370 may be formed of a plurality of layers.

The conductive layer 370 has an effect of minimizing mechanical damage (breaking or peeling, etc.) that may occur in the manufacturing process of the light emitting device.

In addition, the conductive layer 370 has an effect of preventing the metal material constituting the support substrate 310 or the bonding layer (not shown) from being diffused into the light emitting structure 330.

Referring back to FIG. 4, the second electrode layer 360 may selectively use a metal and a transparent conductive layer, and provide power to the light emitting structure 330. The second electrode layer 360 may include a conductive material. For example, nickel (Ni), platinum (Pt), ruthenium (Ru), iridium (Ir), rhodium (Rh), tantalum (Ta), molybdenum (Mo), titanium (Ti), silver (Ag), tungsten (W), copper (Cu), chromium (Cr), palladium (Pd), vanadium (V), cobalt (Co), niobium (Nb), zirconium (Zr), indium tin oxide (ITO), Aluminum zinc oxide (AZO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide (IGZO), indium gallium (IGTO) tin oxide), antimony tin oxide (ATO), gallium zinc oxide (GZO), IrO _x , RuO _x , RuO _x / ITO, Ni / IrO _x / Au, or Ni / IrO _x / Au / ITO Can be. However, it is not limited thereto.

In addition, the second electrode layer 360 may be formed of a single layer or multiple layers of a reflective electrode material having ohmic characteristics.

The second electrode layer 360 is a structure of an ohmic layer 361 / reflection layer 362 / bonding layer (not shown), a laminated structure of the ohmic layer 361 / reflection layer 362, or a reflective layer (including ohmic) 362. ) / Bonding layer (not shown), but is not limited thereto.

The ohmic layer 361 is in ohmic contact with a lower surface of the light emitting structure (eg, the second conductivity-type semiconductor layer 333), and may be formed in a layer or a plurality of patterns. The ohmic layer 361 may selectively use a light-transmitting conductive layer and a metal. For example, indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), and indium aluminum zinc (AZO) oxide), IGZO (indium gallium zinc oxide), IGTO (indium gallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zinc oxide), IZON (IZO Nitride), AGZO (Al- Ga ZnO), IGZO (In-Ga ZnO), ZnO, IrOx, RuOx, NiO, RuOx / ITO, Ni / IrOx / Au, and Ni / IrOx / Au / ITO, Ag, Ni, Cr, Ti, Al, Rh , Pd, Ir, Sn, In, Ru, Mg, Zn, Pt, Au, can be formed including at least one of Hf, and is not limited to these materials. The ohmic layer 361 may be formed by sputtering or electron beam deposition. The reflective layer 362 reflects the light toward the upper direction of the light emitting device 300 when some of the light generated from the active layer 332 of the light emitting structure 330 is directed toward the support substrate 310. The light extraction efficiency of 300 may be improved.

The reflective layer 362 may be formed of a metal layer including aluminum (Al), silver (Ag), nickel (Ni), platinum (Pt), rhodium (Rh), or an alloy containing Al, Ag, Pt, or Rh, It may be formed in multiple layers using the metal material and light transmitting conductive materials such as IZO, IZTO, IAZO, IGZO, IGTO, AZO, and ATO. In addition, the reflective layer 362 may be laminated with IZO / Ni, AZO / Ag, IZO / Ag / Ni, AZO / Ag / Ni, or the like. In addition, when the reflective layer 362 is formed of a material in ohmic contact with the light emitting structure (eg, the second conductivity type semiconductor layer 333), the ohmic layer 361 may not be separately formed, but is not limited thereto.

Although the reflective layer 362 and the ohmic layer 361 are described as having the same width and length, at least one of the width and the length may be different, but is not limited thereto.

The bonding layer (not shown) may be a barrier metal or a bonding metal, for example, titanium (Ti), gold (Au), tin (Sn), nickel (Ni), chromium (Cr), and gallium (Ga). ), Indium (In), bismuth (Bi), copper (Cu), silver (Ag) or tantalum (Ta).

The first transparent conductive layer 341 may be formed on the first conductive semiconductor layer 331, and the first electrode 350 penetrates through the first transparent conductive layer 341 to form the first conductive semiconductor layer. It may be formed to contact the 331.

In addition, the second transparent conductive layer 342 may be formed to cover the first electrode 350, and may include an opening to expose a portion of the upper surface of the first electrode 350.

5 to 10 are views showing a manufacturing process of the light emitting device according to the embodiment.

Referring to FIG. 5, first, the buffer layer 120, the first conductive semiconductor layer 131, the active layer 132, and the second conductive semiconductor layer 133 are sequentially formed on the growth substrate 110.

The growth substrate 110 may be selected from the group consisting of sapphire substrate (Al ₂ O ₃ ), GaN, SiC, ZnO, Si, GaP, InP, and GaAs.

The buffer layer 120 may be formed of a combination of Group 3 and Group 5 elements, or may be formed of any one of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, and AlInN, and dopants may be doped.

An undoped semiconductor layer may be formed on the growth substrate 110 or the buffer layer 120, and either or both of the buffer layer 120 and the undoped conductive semiconductor layer (not shown) are formed. It may or may not be formed and is not limited to this structure.

The first conductive semiconductor layer 131, the active layer 132, and the second conductive semiconductor layer 133 may be sequentially formed on the growth substrate 110.

The first conductive semiconductor layer 131 injects silane gas (SiH4) containing N-type impurities such as trimethyl gallium gas (TMGa), ammonia gas (NH3), nitrogen gas (N2), and silicon (Si) into the chamber. Can be formed.

The active layer 132 may be grown in a nitrogen atmosphere while injecting trimethyl gallium gas (TMGa) and trimethyl indium gas (TMIn), and a single quantum well structure, a multi quantum well structure (MQW), and a quantum line It may be formed of at least one of a wire structure or a quantum dot structure.

The second conductivity-type semiconductor layer 133 is formed in a chamber of 960? At high temperatures, hydrogen may be used as a carrier gas to inject trimethyl gallium gas (TMGa), trimethyl aluminum gas (TMAl), bicetyl cyclopentadienyl magnesium (EtCp2Mg) {Mg (C2H5C5H4) 2}, or the like. It is not limited.

Then, the manufacturing process of the horizontal light emitting device and the vertical light emitting device is different.

6 and 7 illustrate a manufacturing process of the horizontal light emitting device after the process shown in FIG. 5.

6 and 7, the transparent conductive layer 140 may be formed on the second conductive semiconductor layer 133, and the transparent conductive layer 140 may be etched by a depth of 500 to 2000 μs to form a recess. Can be. A branch electrode 152 may be formed in the concave portion 145, and an electrode pad 151 may pass through the transparent conductive layer 140.

Although not shown in the drawings, a first electrode is formed by etching a mesa from the second conductive semiconductor layer 133 to a portion of the first conductive semiconductor layer 131 by a reactive ion etching (RIE) method. can do.

8 to 10 are views showing a manufacturing process of the vertical light emitting device after the process shown in FIG.

Referring to FIG. 8, a second electrode layer 360 may be formed on the second conductive semiconductor layer 133, and a support substrate 310 on which the conductive layer 370 is disposed may be bonded and bonded. In this case, the growth substrate 110 disposed on the first conductivity type semiconductor layer 131 may be separated.

In this case, the growth substrate 110 may be removed by a physical or / and chemical method, and the physical method may be removed by, for example, a laser lift off (LLO) method.

Meanwhile, the buffer layer 120 may be removed after the growth substrate 110 is removed. In this case, the buffer layer 120 may be removed through a dry or wet etching method or a polishing process.

In addition, although not shown, the outer area of the light emitting structure 130 may be etched to have an inclination, and a passivation (not shown) may be formed on a part or the entire area of the outer circumferential surface of the light emitting structure 130. The passivation may be made of an insulating material.

9 and 10, a first transparent electrode layer 341 may be formed on the first conductive semiconductor layer 131, penetrating through the first transparent electrode layer 341, and forming a first conductive semiconductor layer 131. ), The first electrode 350 may be formed.

In addition, a second transparent conductive layer 342 may be formed to cover the first transparent conductive layer 341 and the first electrode 350, and the second transparent conductive layer 342 may have an upper surface of the first electrode 350. It may include an opening to expose a portion.

At least one process in the process sequence illustrated in FIGS. 5 to 10 may be reversed, but is not limited thereto.

11 is a cross-sectional view showing a cross section of a light emitting device package including a light emitting device according to the embodiment.

Referring to FIG. 11, the light emitting device package 400 according to the embodiment includes a body 410 in which a cavity is formed, a light source unit 420 mounted in a cavity of the body 410, and an encapsulant 450 filled in the cavity. can do.

The body 410 is made of a resin material such as polyphthalamide (PPA), silicon (Si), aluminum (Al), aluminum nitride (AlN), photosensitive glass (PSG), polyamide 9T (PA9T) ), Neo geotactic polystyrene (SPS), a metal material, sapphire (Al2O3), beryllium oxide (BeO), a printed circuit board (PCB, Printed Circuit Board), it may be formed of at least one. The body 410 may be formed by injection molding, etching, or the like, but is not limited thereto.

The light source unit 420 may be mounted on the bottom surface of the body 410. For example, the light source unit 420 may be any one of the light emitting devices illustrated and described with reference to FIGS. 1A to 10. The light emitting device may be, for example, a colored light emitting device emitting light of red, green, blue, white, or the like, or an ultraviolet (UV) light emitting device emitting ultraviolet light, but is not limited thereto. In addition, one or more light emitting devices may be mounted.

The body 410 may include a first lead frame 430 and a second lead frame 440. The first lead frame 430 and the second lead frame 440 may be electrically connected to the light source unit 420 to supply power to the light source unit 420.

In addition, the first lead frame 430 and the second lead frame 440 may be electrically separated from each other, and may reflect light generated from the light source unit 420 to increase light efficiency, and may also be generated in the light source unit 420. The waste heat to the outside.

11 illustrates that both the first lead frame 430 and the second lead frame 440 are bonded to the light source unit 420 by the wire 460, but is not limited thereto. In particular, in the case of a vertical light emitting device Any one of the first lead frame 430 and the second lead frame 440 may be bonded to the light source unit 420 by the wire 460, and may be connected to the light source unit 420 without the wire 460 by a flip chip method. It may be electrically connected.

The first lead frame 430 and the second lead frame 440 is a metal material, for example, titanium (Ti), copper (Cu), nickel (Ni), gold (Au), chromium (Cr), tantalum Aluminum (Ta), Platinum (Pt), Tin (Sn), Silver (Ag), Phosphorus (P), Aluminum (Al), Indium (In), Palladium (Pd), Cobalt (Co), Silicon (Si), It may include one or more materials or alloys of germanium (Ge), hafnium (Hf), ruthenium (Ru), iron (Fe). In addition, the first lead frame 430 and the second lead frame 440 may be formed to have a single layer or a multilayer structure, but is not limited thereto.

The encapsulant 450 may be filled in the cavity, and may include a phosphor (not shown). The encapsulant 450 may be formed of transparent silicone, epoxy, and other resin materials, and may be formed by filling in a cavity and then ultraviolet or thermal curing.

The phosphor (not shown) may be selected according to the wavelength of light emitted from the light source unit 420 so that the light emitting device package 400 may implement white light.

Phosphors (not shown) included in the encapsulant 450 may include blue light emitting phosphors, cyan light emitting phosphors, green light emitting phosphors, yellow green light emitting phosphors, yellow light emitting phosphors, and yellow red light emitting phosphors according to wavelengths of light emitted from the light source unit 420. One of orange luminescent phosphor, and red luminescent phosphor can be applied.

That is, the phosphor (not shown) may be excited by the light having the first light emitted from the light source unit 420 to generate the second light. For example, when the light source unit 420 is a blue light emitting diode and the phosphor (not shown) is a yellow phosphor, the yellow phosphor may be excited by blue light to emit yellow light, and blue light and blue generated from the blue light emitting diode As the yellow light generated by being excited by the light is mixed, the light emitting device package 400 may provide white light.

12A is a perspective view illustrating a lighting apparatus including a light emitting device module according to an embodiment, and FIG. 12B is a cross-sectional view illustrating a cross-sectional view taken along line C-C 'of the lighting apparatus of FIG. 12A.

That is, FIG. 12B is a cross-sectional view of the lighting apparatus 500 of FIG. 12A cut in the plane of the longitudinal direction Z and the height direction X, and viewed in the horizontal direction Y.

12A and 12B, the lighting apparatus 500 may include a body 510, a cover 530 fastened to the body 510, and a closing cap 550 positioned at both ends of the body 510. have.

The light emitting device module 540 is fastened to the lower surface of the body 510, and the body 510 is electrically conductive so that heat generated from the light emitting device package 544 can be discharged to the outside through the upper surface of the body 510. The heat dissipation effect may be formed of an excellent metal material, but is not limited thereto.

In particular, the light emitting device module 540 may include a sealing part (not shown) surrounding the light emitting device package 544, so that the infiltration of foreign matters may be prevented, so that the reliability may be improved. Implementation of.

The light emitting device package 544 may be mounted on the substrate 542 in multiple colors and in multiple rows to form a module. The light emitting device package 544 may be mounted at the same interval or may be mounted with various separation distances as necessary to adjust brightness. As the substrate 542, a PCB made of a metal core PCB (MCPCB) or a FR4 material may be used.

The cover 530 may be formed in a circular shape to surround the lower surface of the body 510, but is not limited thereto.

The cover 530 protects the internal light emitting device module 540 from external foreign matters. In addition, the cover 530 may include diffusing particles to prevent glare of the light generated from the light emitting device package 544 and to uniformly emit light to the outside, and may also include at least one of an inner surface and an outer surface of the cover 530. A prism pattern or the like may be formed on either side. In addition, a phosphor may be applied to at least one of an inner surface and an outer surface of the cover 530.

On the other hand, since the light emitted from the light emitting device package 544 is emitted to the outside through the cover 530, the cover 530 should be excellent in light transmittance, and sufficient to withstand the heat generated in the light emitting device package 544 The cover 530 should include heat resistance, and the cover 530 may include polyethylene terephthalate (PET), polycarbonate (PC), polymethyl methacrylate (PMMA), or the like. It is preferably formed of a material.

The closing cap 550 is located at both ends of the body 510 and may be used for sealing a power supply (not shown). In addition, the closing cap 550 is formed with a power pin 552, the lighting device 500 according to the embodiment can be used immediately without a separate device in the terminal from which the existing fluorescent lamps are removed.

13 and 14 are exploded perspective views of a liquid crystal display including an optical sheet according to an embodiment.

FIG. 13 illustrates an edge-light method, and the liquid crystal display 600 may include a liquid crystal display panel 610 and a backlight unit 670 for providing light to the liquid crystal display panel 610.

The liquid crystal display panel 610 may display an image using light provided from the backlight unit 670. The liquid crystal display panel 610 may include a color filter substrate 612 and a thin film transistor substrate 614 facing each other with a liquid crystal interposed therebetween.

The color filter substrate 612 may implement a color of an image displayed through the liquid crystal display panel 610.

The thin film transistor substrate 614 is electrically connected to the printed circuit board 618 on which a plurality of circuit components are mounted through the driving film 617. The thin film transistor substrate 614 may apply a driving voltage provided from the printed circuit board 618 to the liquid crystal in response to a driving signal provided from the printed circuit board 618.

The thin film transistor substrate 614 may include a thin film transistor and a pixel electrode formed of a thin film on another transparent material such as glass or plastic.

The backlight unit 670 may include a light emitting device module 620 for outputting light, a light guide plate 630 for changing the light provided from the light emitting device module 620 into a surface light source, and providing the light to the liquid crystal display panel 610. Reflective sheet for reflecting the light emitted to the light guide plate 630 to the plurality of films 650, 666, 664 and the light guide plate 630 to uniform the luminance distribution of the light provided from the 630 and improve the vertical incidence ( 640).

The light emitting device module 620 may include a PCB substrate 622 such that a plurality of light emitting device packages 624 and a plurality of light emitting device packages 624 may be mounted to form a module.

In particular, the light emitting device module 620 may include a seal (not shown) surrounding the light emitting device package 624 to prevent foreign matter from penetrating, thereby improving reliability, and also providing reliable backlight unit 670. Implementation of.

On the other hand, the backlight unit 670 is a diffusion film 666 for diffusing the light incident from the light guide plate 630 toward the liquid crystal display panel 610, and a prism film 650 for condensing the diffused light to improve vertical incidence. ), And may include a protective film 664 to protect the prism film 650.

14 is an exploded perspective view of a liquid crystal display device including the optical sheet according to the embodiment. However, the parts shown and described in FIG. 13 will not be repeatedly described in detail.

14 is a direct view, the liquid crystal display 700 may include a liquid crystal display panel 710 and a backlight unit 770 for providing light to the liquid crystal display panel 710.

Since the liquid crystal display panel 710 is the same as that described with reference to FIG. 13, a detailed description thereof will be omitted.

The backlight unit 770 includes a plurality of light emitting device modules 723, a reflective sheet 724, a lower chassis 730 in which the light emitting device modules 723 and the reflective sheet 724 are accommodated, and an upper portion of the light emitting device module 723. It may include a diffusion plate 740 and a plurality of optical film 760 disposed in the.

LED Module 723 A plurality of light emitting device packages 722 and a plurality of light emitting device packages 722 may be mounted to include a PCB substrate 721 to form a module.

In particular, the light emitting device module 723 may include a sealing part (not shown) surrounding the light emitting device package 722 to prevent foreign matter from penetrating, thereby improving reliability, and also providing reliable backlight unit 770. Implementation of.

The reflective sheet 724 reflects the light generated from the light emitting device package 722 in the direction in which the liquid crystal display panel 710 is located to improve light utilization efficiency.

Meanwhile, light generated by the light emitting device module 723 is incident on the diffuser plate 740, and the optical film 760 is disposed on the diffuser plate 740. The optical film 760 includes a diffusion film 766, a prism film 750, and a protective film 764.

Although the above has been illustrated and described with respect to preferred embodiments of the present invention, the present invention is not limited to the specific embodiments described above, but in the art to which the invention pertains without departing from the spirit of the invention as claimed in the claims. Various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

Although the above has been illustrated and described with respect to preferred embodiments of the present invention, the present invention is not limited to the specific embodiments described above, but in the art to which the invention pertains without departing from the spirit of the invention as claimed in the claims. Various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

110: growth substrate 120: buffer layer
131: first conductive semiconductor layer 132: active layer
133: second conductive semiconductor layer 140: transparent conductive layer
151: electrode pad 152: branch electrode

Claims (11)

A light emitting structure sequentially comprising a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer;
A first transparent conductive layer disposed on the light emitting structure and including a concave portion;
An electrode pad penetrating the first transparent conductive layer to be in contact with the light emitting structure;
A branch electrode connected to the electrode pad and disposed in the recess;
A second transparent conductive layer disposed on the first transparent conductive layer, the branch electrode and the electrode pad;
The second transparent conductive layer has a light emitting device including an opening that exposes a portion of the upper surface of the electrode pad. delete delete The method of claim 1,
The first transparent conductive layer and the second transparent conductive layer is a light emitting device comprising the same material. The method of claim 1,
The thickness of the second transparent conductive layer is thinner than the thickness of the first transparent conductive layer. The method of claim 1,
The first transparent conductive layer and the second transparent conductive layer is a light emitting device comprising at least one of ITO, IZO, ITZO and ZnO. The method of claim 1,
The concave portion has a depth of 500 to 2000 500. The method of claim 1,
The first transparent conductive layer has a thickness of 600 to 2500Å light emitting device. The method of claim 1,
The concave portion of the light emitting device is wider toward the top. delete delete

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